Bone fastener for a spinal surgical system

ABSTRACT

A bone fastener includes a receiver defining a longitudinal axis and extending between a proximal end and a distal end, the proximal end including a first wall and a second wall that define an implant cavity, each wall having a proximal face. At least one of the first wall and the second wall include an extension extending proximally from the proximal face along the longitudinal axis, the extension having a distal end integral with the proximal face and a proximal end including a first locking part configured for fixation with a second locking part of an instrument. A bone penetrating member has a proximal end and a distal end, the proximal end of the bone penetrating member being connected with the distal end of the receiver.

TECHNICAL FIELD

The present disclosure generally relates to medical devices and systemsfor the treatment of bone disorders, and more particularly to a spinalsurgical system which includes a bone fastener and an extenderconfigured to advance and guide components used in the treatment of bonedisorders from outside the body to a location adjacent to a surgicalsite.

BACKGROUND

Spinal disorders such as degenerative disc disease, disc herniation,osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvatureabnormalities, kyphosis, tumor, and fracture may result from factorsincluding trauma, disease and degenerative conditions caused by injuryand aging. Spinal disorders typically result in symptoms including pain,nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercisecan be effective, however, may fail to relieve the symptoms associatedwith these disorders. Surgical treatment of these spinal disordersincludes discectomy, laminectomy, fusion and implantable prosthetics. Aspart of these surgical treatments, spinal constructs such as vertebralrods are often used to provide stability to a treated region. Rodsredirect stresses away from a damaged or defective region while healingtakes place to restore proper alignment and generally support thevertebral members. During surgical treatment, one or more rods may beattached via one or more bone fasteners to the exterior of two or morevertebral members. This disclosure describes an improvement over theseprior art technologies.

SUMMARY OF THE INVENTION

Accordingly, a spinal surgery system is disclosed that includes a bonefastener and an extension configured to advance and guide componentsused in the treatment of bone disorders from outside the body to alocation adjacent to a surgical site.

In one embodiment, in accordance with the principles of the presentdisclosure, a bone fastener is provided. The bone fastener includes areceiver defining a longitudinal axis and extending between a proximalend and a distal end, the proximal end including a first wall and asecond wall that define an implant cavity. Each wall has a proximalface. At least one of the first wall and the second wall include anextension extending proximally from the proximal face along thelongitudinal axis, the extension having a distal end integral with theproximal face and a proximal end including a first locking partconfigured for fixation with a second locking part of an instrument. Abone penetrating member has a proximal end and a distal end, theproximal end of the bone penetrating member being connected with thedistal end of the receiver.

In one embodiment, a spinal surgical system is provided which includes abone fastener having a receiver defining a longitudinal axis andextending between a proximal end and a distal end. The proximal end ofthe receiver includes a first arm and a second arm that define animplant cavity. Each arm has a proximal face. The first arm has a firstextension integrally connected with the proximal face of the first armalong the longitudinal axis, the first extension having a locking part.The second arm has a second extension integrally connected with theproximal face of the second arm along the longitudinal axis, the secondextension also having a locking part. The bone fastener has a bonepenetrating member connected with the distal end of the receiver. Thesystem also includes an instrument having a first elongated member and asecond elongated member. The first elongated member includes an innersurface defining an elongated axial cavity configured for disposal ofthe first arm and a locking part configured for fixation with thelocking part of the first arm. The second elongated member includes aninner surface defining an elongated axial cavity configured for disposalof the second arm and a locking part configured for fixation with thelocking part of the second arm.

In another embodiment in accordance with the principles of the presentdisclosure, the system includes a bone fastener having a receiverdefining a longitudinal axis and extending between a proximal end and adistal end. The proximal end of the receiver has a first arm and asecond arm that define a U-shaped channel. Each arm has a proximal face.The first arm includes a first extension monolithically formed with theproximal face of the first arm along the longitudinal axis, the firstextension having a protrusion. The second arm includes a secondextension monolithically formed with the proximal face of the second armalong the longitudinal axis, the second extension having a protrusion. Abone penetrating member is connected with the distal end of thereceiver. The system also includes an extender having a first elongatedmember and a second elongated member that define a rod cavitytherebetween. The first elongated member includes an inner surfacedefining an elongated axial cavity configured for disposal of the firstarm and an opening configured for fixation with the protrusion of thefirst arm. The second elongated member includes an inner surfacedefining an elongated axial cavity configured for disposal of the secondarm and an opening configured for fixation with the protrusion of thesecond arm. The system also includes a vertebral rod configured formanipulation within the rod cavity and fixation within the U-shapedchannel.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more readily apparent from thespecific description accompanied by the following drawings, in which:

FIG. 1 is a perspective view of one embodiment of a bone fastener andone embodiment of an extender in accordance with the principles of thepresent disclosure;

FIG. 2 is a perspective view of the bone fastener shown in FIG. 1;

FIG. 2A is a perspective view of the bone fastener;

FIG. 2B is a cross-sectional view of the bone fastener with theextenders;

FIG. 2C is a cross-sectional view of the extender and receiver;

FIG. 3 is another perspective view of the bone fastener shown in FIG. 1;

FIG. 3A is a cross-sectional view of extender having a recess on theinside surface;

FIG. 3B is a cross-sectional view of extender having perforations on theextender;

FIG. 3C is a cross-sectional view of an alternative locking mechanism ofthe present invention;

FIG. 3D is a perspective view of an alternative locking mechanism of thepresent invention;

FIG. 3E is a perspective view of an alternative locking Mechanism of thepresent invention;

FIG. 3F is a perspective view of an alternative locking mechanism of thepresent invention;

FIG. 4 is a perspective view of the extender shown in FIG. 1;

FIG. 5 is a perspective view of a distal end of the extender shown inFIG. 1; and

FIG. 6 is a perspective, close-up view of the distal end of the extendershown in FIG. 5.

Like reference numerals indicate similar parts throughout the figures.

DETAILED DESCRIPTION OF THE INVENTION

The exemplary embodiments of the bone fastener and spinal surgicalsystem disclosed are discussed in terms of medical devices for thetreatment of bone disorders and more particularly, in terms of a spinalsurgery system that includes a bone fastener and an extender configuredto advance and guide components used in the treatment of bone disordersfrom outside the body to a location adjacent to a surgical site. It iscontemplated that the disclosed spinal surgery system may be employedwith minimally invasive systems and procedures which insert implants,instruments and other devices to perform operations through small skinincisions thereby allowing optimization of devices used in suchprocedures.

It is envisioned that the present disclosure may be employed to treatspinal disorders such as, for example, degenerative disc disease, discherniation, osteoporosis, spondylolisthesis, stenosis, scoliosis andother curvature abnormalities, kyphosis, tumor and fractures. It isfurther envisioned that the present disclosure may be employed withsurgical treatments including open surgery and minimally invasiveprocedures, of such disorders, such as, for example, discectomy,laminectomy, fusion, bone graft, implantable prosthetics and/or dynamicstabilization applications. It is contemplated that the presentdisclosure may be employed with other osteal and bone relatedapplications, including those associated with diagnostics andtherapeutics. It is further contemplated that the disclosed bonefastener may be employed in a surgical treatment with a patient in aprone or supine position, employing a posterior, lateral or anteriorapproach. The present disclosure may be employed with procedures fortreating the lumbar, cervical, thoracic and pelvic regions of a spinalcolumn.

The present invention may be understood more readily by reference to thefollowing detailed description of the invention taken in connection withthe accompanying drawing figures, which form a part of this disclosure.It is to be understood that this invention is not limited to thespecific devices, methods, conditions or parameters described and/orshown herein, and that the terminology used herein is for the purpose ofdescribing particular embodiments by way of example only and is notintended to be limiting of the claimed invention. Also, as used in thespecification and including the appended claims, the singular forms “a,”“an,” and “the” include the plural, and reference to a particularnumerical value includes at least that particular value, unless thecontext clearly dictates otherwise. Ranges may be expressed herein asfrom “about” or approximately one particular value and/or to “about” or“approximately” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,' it willbe understood that the particular value forms another embodiment.

The following discussion includes a description of a spinal surgerysystem that includes a bone fastener and an extender configured toadvance and guide components used in the treatment of bone disordersfrom outside the body to a location adjacent to a surgical site. Relatedcomponents and exemplary methods of employing the spinal surgery systemin accordance with the principles of the present disclosure as well asalternate embodiments are also disclosed. Reference will now be made indetail to the exemplary embodiments of the present disclosure, which areillustrated in the accompanying figures. Turning now to FIGS. 1-3, thereis illustrated components of a spinal surgical system 30 in accordancewith the principles of the present disclosure.

The components of spinal surgical system 30 are fabricated frommaterials suitable for medical applications, including metals, polymers,ceramics, biocompatible materials and/or their composites, depending onthe particular application and/or preference of a medical practitioner.For example, a bone fastener 32, and extender 100 and/or a vertebralrod, discussed below, of spinal surgical system 30 can be fabricatedfrom materials such as commercially pure titanium, titanium alloys,Grade 5 titanium, super-elastic titanium alloys, cobalt-chrome alloys,stainless steel alloys, superelastic metallic alloys (e.g. Nitinol,super elasto-plastic metals, such as GUM METAL® manufactured by ToyotaMaterial Incorporated of Japan), thermoplastics such aspolyaryletherketone (PAEK) including polyetheretherketone (PEEK),polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon fiberreinforced PEEK composites, PEEK-BaSO₄ composites, ceramics andcomposites thereof such as calcium phosphate (e.g. SKELITE™ manufacturedby Biologix Inc.), rigid polymers including polyphenylene, polyimide,polyimide, polyetherimide, polyethylene, polyurethanes of any durometer,epoxy and silicone. Different components of spinal surgical system 30may have alternative material composites to achieve various desiredcharacteristics such as strength, rigidity, elasticity, compliance,biomechanical performance, durability and radiolucency or imagingpreference. The components of spinal surgical system 30 may also befabricated from a heterogeneous material such as a combination of two ormore of the above-described materials.

It is envisioned that the components of spinal surgical system 30 can bemanufactured via various methods. For example, bone fastener 32 can bemanufactured and assembled via injection-molding, insert-molding,overmolding, compression molding, transfer molding, co-extrusion,pultrusion, dip-coating, spray-coating, powder-coating, porous-coating,machining, milling from a solid stock material and their combinations.One skilled in the art, however, will realize that such materials andfabrication methods suitable for manufacture and assembly, in accordancewith the present disclosure, would be appropriate.

Bone fastener 32, such as for example, a multi-axial of angledbone-fastener, fixed screw or spinal hook, is employed with spinalsurgical system 30, which is configured for attachment to bone, such as,for example, one or more vertebrae during surgical treatment of a spinaldisorder, examples of which are discussed herein. Bone fastener 32includes a receiver 34 defining a longitudinal axis I and extendingbetween a proximal end 36 and a distal end 38. Receiver 34 is configuredto receive and couple a spinal construct, such as vertebral rod, forexample, to bone fastener 32. Proximal end 36 includes a first wall,such as, for example, a first arm 40 and a second wall, such as, forexample, a second arm 42 that define an implant cavity, such as, forexample, a channel 44. In one embodiment, channel 44 has a generallyU-shaped cross-section. However, it is envisioned that channel 44 mayhave other cross-sectional configurations, including, for example,V-shaped, polygonal or tapered.

First and second arms 40, 42 are disposed opposite one another and eachhave an arcuate shape. First arm 40 has a width w, a thickness t andincludes a proximal face 46 and a first extension 48 monolithicallyformed with proximal face 46 of first extension 48. First extension 48extends proximally from proximal face 46 along longitudinal axis Ibetween proximal end 52 and distal end 53. Second arm 42 has a widthw_(1,) a thickness t₁ and includes a proximal face 54 and a secondextension 56 monolithically formed with proximal face 54 of second arm42. Second extension 56 extends proximally from proximal face 54 alonglongitudinal axis I between a proximal end 60 and a distal end 61. It isenvisioned that first and second extensions 48, 56 may be removablyattached with proximal faces 46, 54 such that at least a portion offirst and second extensions 48, 56 may be separated from receiver 34.For example, first and second extensions 48, 56 may be clipped toproximal faces 46, 54 of receiver 34 via clips positioned at distal ends53, 61 of first and second extensions 48, 56. Alternatively, distal ends53, 61 of first and second extensions 48, 56 may be positioned incorresponding recesses in proximal faces 46, 54 of first and second arms40, 42 so as to be held in place. In an alternative embodiment, proximalface 46 does not exist and is in accordance with the principles of thepresent invention is shown in FIG. 3B. In FIG. 3B, perforations 24 arelocated at the bone penetrating member and can act as a break-off regionfor the device. It is envisioned that there can be one row ofperforations including one or a plurality of perforations or multiplerows.

First and second extensions 48, 56 are substantially similar to oneanother, and are sized and shaped to extend from proximal faces 46, 54of first and second arms 40, 42. First extension 48 and/or secondextension 56 has/have a substantially uniformly continuous even surfaceconfiguration. That is, first extension 48 and/or second extension 56has/have smooth surfaces that are not interrupted by any gaps orprotrusions. In one embodiment, first and second extensions 48, 56 haveinner surfaces and outer surfaces that are planar. However, it isenvisioned that first and second extensions 48, 56 may have an arcuatesurface configuration such that inner surfaces and/or outer surfaces offirst and second extensions 48, 56 correspond to the arcuate shape offirst and second walls 40, 42 from which first and second extensions 48,56 extend. That is, the inner surfaces of first and second extensions48, 56 can be concavely curved, while the outer surfaces thereof areconvexly curved. Other configurations in this respect are alsoenvisioned by the present disclosure and fall within the spirit of thepresent invention.

First extension 48 has a width w₂ that is less than width w of first arm40, as shown in FIG. 2, and second extension 56 has a width w₃ that isless than width w₁ of second arm 42, as shown in FIG. 3. In accordancewith the principles of the present disclosure, it is envisioned thatfirst and second extensions 48, 56 may have a width that isapproximately equal to widths w and w₁ of first and second arms 40, 42.First extension 48 has a thickness t₂ that is less than thickness t offirst arm 40, and second extension 56 has a thickness t₃ that is lessthan thickness t₁ of second arm 42. Similarly it is also envisioned thatfirst and second extensions 48, 56 may have a thickness that isapproximately equal to thicknesses t and t₁ of first and second arms 40,42.

First and second extensions 48, 56 are substantially parallel to oneanother and have a length that allows proximal ends 52, 60 to bepositioned outside a patient's body, while distal ends 53, 61 arecoupled to proximal faces 46, 54 of receiver 34 when bone fastener 32 isfully implanted in a vertebra and receiver 34 is positioned adjacent tothe vertebrae. In the alternative, first and second extensions 48, 56are substantially parallel to one another and have a length that allowsproximal ends 52, 60 to be within a retractor and accessible, but notoutside the body, when used in a mini-open surgical procedure. First andsecond extensions 48, 56 define a slot 57 which is aligned with channel44 in receiver 34 such that slot 57 and channel 44 are continuous toallow a vertebral construct, such as, for example, a vertebral rod, tomove within slot 57 and into channel 44.

First extension 48 includes a first locking part, such as, for example,a protrusion 50 at proximal end 52 thereof, and second extension 56includes a first locking part, such as, for example, a protrusion 58 atproximal end 60 thereof. Protrusions 50, 58 are disposed on the outersurfaces of first and second extensions 48, 56 and are configured forfixation with a second locking part of an instrument, such as, forexample, extender 100 so as to fix bone fastener 32 in position andlimit relative motion between bone fastener 32 and extender 100, as willbe described. In an alternative embodiment, a protrusion can bepositioned on the inner diameter of the outer body and the screwextension can be equipped with a cavity configured to mate with theprotrusion on the outer body. This arrangement fixes bone fastener 32 inposition and limits relative motion between bone fastener 32 andextender 100.

In one embodiment, protrusions 50, 58 have a shape that is round oroval. However, it is envisioned that protrusions 50, 58 can be variouslyconfigured with regard to size and shape, and the shape may be selectedfrom the group consisting of rectangular, triangular, polygonal andhexagonal, for example. It is also envisioned that first and second arms40, 42 may include alternate locking or fastening parts to fix bonefastener 32 with extender 100 such as, integral connection, threadedengagement, clips, friction fit, interference fit, pins and/or adhesive.

Bone fastener 32 includes an integral connection 68 extending betweenfirst extension 48 and proximal face 46 of first arm 40, as shown inFIG. 2, and an integral connection 70 extending between second extension56 and proximal face 54 of second arm 42, as shown in FIG. 3. In oneembodiment, integral connections 68, 70 are disposed at distal ends 53,61 of first and second extensions 48, 56, where second extensions 48, 56meet proximal faces 46, 54 of first and second arms 40, 42. It is alsoenvisioned that integral connections 68, 70 may be disposed at anyportion along the length of first and second extensions 48, 56. Integralconnection 68 has a width w₄ that is less than width of first extension48 and integral connection 70 has a width w₅ that is less than width w₃of second extension 56. The reduced widths of integral connections 68,70 are due to reliefs 80, 82 (best seen in FIGS. 2 and 3) that aredisposed in the outer surfaces thereof which form a recess extendingperpendicularly relative to longitudinal axis I. In one embodiment, theintegral connection is a portion of the extension that has a reducedcross-sectional area when compared to the rest of the extension. Thisreduced area, either due to perforations, notches, recesses or otherconfigurations, allows a break-off section of the extensions. In anotherembodiment, reliefs 80, 82 have arcuate cross-sectional configurations.However, it is envisioned that the reliefs 80, 82 may have othercross-sectional configurations, including, for example, triangular,polygonal or tapered.

Integral connection 68 has a thickness that is less than thickness t₂ offirst extension 48 and integral connection 70 has a thickness that isless than thickness t₃ of second extension 56. However, it is envisionedthat widths w₄, w₅ of integral connections 68, 70 may be approximatelyequal to widths w₂, w₃ of first and second extensions 48, 56. It is alsoenvisioned that the thicknesses of integral connections 68, 70 may beapproximately equal to thicknesses t₂ and t₃ of first and secondextensions 68, 70. The recess, notches or groves can also be located onthe inside of the extension as shown in FIG. 3A. The reduced thicknessesof integral connections 68, 70 is due to notches 76, 78 extending intothe side surfaces thereof. In one embodiment, notches 76, 78 havearcuate cross-sectional configurations. However, it is envisioned thatnotches 76, 78 may have other cross-sectional configurations, including,for example, triangular, polygonal or tapered. It is this reduction inthe cross-sectional area due to the recesses, notches or perforationsthat provide for the break-off mechanism of the extensions.

The inner surfaces of first and second extensions 48, 56 are continuouswith the inner surfaces of integral connections 68, 70 such that thereare no gaps therebetween. It is envisioned that integral connections 68,70 may be formed from a material which is different from the materialused to form receiver 34 and/or first and second extensions 48, 56 suchthat integral connections 68, 70 break off from the receiver 34 when aforce is applied thereto thereby allowing at least a portion of firstand second extensions 48, 56 to be separated from receiver 34. It isenvisioned that these notches can have different forms, shapes anddepths into the side surfaces so as to provide different break-ofprofiles of the extensions 48, 56 from the receiver 34. That is,different forms, shapes and depths of the notches into the side surfacesof the extensions will require different amounts of force to break-offthe extensions 48, 56 from receiver 34.

Bone fastener 32 further includes a bone-penetrating member 62, such asa multi-axial screw, fixed screw or spinal hook, that extends between aproximal end 64 and a distal end 66 and is configured to connect withdistal end 38 of receiver 34. Bone penetrating member 62 is configuredfor fixation within vertebrae and has a cylindrical shaft configuration.In one embodiment of the present disclosure, bone penetrating member 62tapers from a first width w₆ at proximal end 64 to a second, reducedwidth w; at distal end 66. Receiver 34 has a bore in distal end 38configured to receive proximal end 64 of bone penetrating member 62 tocouple bone penetrating member 62 to receiver 34. As such, the bore indistal end 38 of receiver 34 has a diameter which is greater than widthw₆ in proximal end 64 of bone penetrating member 62 such that proximalend 64 of bone penetrating member 62 is seated within the bore inproximal end 36 of receiver 34. Bone penetrating member 62 islongitudinally aligned with receiver 34 along longitudinal axis I. Inone embodiment, bone penetrating member 62 is rotationally fixed toreceiver 34 so as to rotate around one or more axis. That is, bonepenetrating member 62 is pivotable to a plurality of axial orientationsrelative to receiver 34. It is contemplated that bone penetrating member62 or portions thereof can have various dimensions, for example, withregard to length, width, diameter and thickness. It is furthercontemplated that the cross-sectional geometry may have variousconfigurations including, for example, round, oval, rectangular,irregular, consistent, variable, uniform and non-uniform.

As shown in FIGS. 1 and 4-6, spinal surgical system 30 further includesextender 100 extending between a proximal end 101 and a distal end 103opposite proximal end 101. Extender 100 includes upper and lowersurfaces 116, 118 extending between side surfaces 120, 122. In oneembodiment, upper and lower surfaces 116, 118 are planar and sidesurfaces 120, 122 are both convexly curved. However, it is envisionedthat upper and lower surfaces 116, 118 and side surfaces 120, 122 mayall be convexly curved, such that extender 100 has a cylindricalcross-section. Alternatively, upper and lower surfaces 116, 118 and sidesurfaces 120, 122 may be planar, such that extender 100 has arectangular or square cross-section. It is contemplated that thecross-sectional geometry of extender 100 may have various configurationsincluding, for example, round, oval, polygonal, irregular, consistent,variable, uniform and non-uniform.

Extender 100 includes a first elongated member 102 and a secondelongated member 104 that define a rod cavity 106 therebetween. In oneembodiment, first and second elongated members 102, 104 are integrallyconnected to one another. However, it is envisioned that first andsecond elongated members 102, 104 may be separate from one another andare connected via dips, a friction fit, an interference fit, pins and/oran adhesive. Rod cavity 106 may be used to facilitate positioning of aspinal construct, such as a vertebral rod, relative to bone fastener 32.Rod cavity 106 extends longitudinally to distal end 103 and throughupper and lower surfaces 116, 118 of extender 100 terminating prior toproximal end 101. That is, rod cavity 106 forms an opening throughdistal end 103 and upper and lower surfaces 116, 118, but does notextend through proximal end 101. First and second elongated members 102,104 are coupled to one another at distal end 101. Rod cavity 106terminates at the point where the first and second elongated members102, 104 couple. Rod cavity 106 is configured so that a vertebralconstruct, such as vertebral rod, and/or an instrument can pass down thecavity.

In one embodiment, rod cavity 106 has a length such that rod cavity 106is accessible outside the body of a patient when bone fastener 32 isfully implanted in a vertebra. However, it is envisioned that the lengthand width of rod cavity 106 may be varied depending upon, for example,the particular methods, instruments and/or vertebral constructs beingemployed. Rod cavity 106, slot 57 between first and second extensions48, 56 and channel 44 between first and second arms 40, 42 arecontinuous and define a pathway from an incision in the skin of apatient to a location adjacent a surgical site for the delivery ofimplants, instruments, and/or other devices.

First elongated member 102 includes an inner surface defining anelongated axial cavity 108 configured for disposal of first arm 40 and acavity defining a second locking part, such as, for example, an opening110 configured for fixation with protrusion 50 of first extension 48.Second elongated member 104 includes an inner surface defining anelongated axial cavity 112 configured for disposal of second arm 42 anda cavity defining a second locking part, such as, for example, anopening 114, configured for fixation with protrusion 58 of secondextension 56. Openings 110, 114 are configured to receive protrusions50, 58 of bone fastener 32. In one embodiment, openings 110, 114 areoval or round. However, it is envisioned that openings 110, 114 can bevariously configured with regard to size and shape, and may have a shapewhich is rectangular, triangular, hexagonal, or any other shape thatcorresponds to the shape of protrusions 50, 58 such that protrusions 50,58 may be received within openings 110, 114. Openings 110, 114 mayextend through side surfaces 120, 122. However, it is envisioned thatopenings 110, 114 may extend through upper and lower surfaces 116, 118.Alternatively, openings 110, 114 may extend into side surfaces 120, 122without extending through the same such that protrusions 50, 58 do notextend through extender 100 when protrusions 50, 58 are received withinopenings 110, 114.

Extender 100 is disposed about at least a portion of bone fastener 32such that extender 100 is coaxially disposed about bone fastener 32. Inparticular, first and second extensions 48, 56 of bone fastener 32 areinserted into distal end 103 of extender 100, leading with proximal ends52, 60 of first and second extensions 48, 56. Bone fastener 32 isadvanced longitudinally through extender 100 toward proximal end 101 ofextender 100 with first and second extensions 48, 56 of bone fastener 32parallel to side surfaces 120, 122 of extender 100. Bone fastener 32 isadvanced until protrusions 50, 58 of first and second extensions 48, 56are received within openings 110, 114, which connects bone fastener 32with extender 100. Protrusions 50, 58 are sized and configured to bereceived within openings 110, 114 such that protrusions 50, 58 occupy asignificant portion of openings 110, 114 to prevent movement of bonefastener 32 relative to extender 100 when protrusions 50,58 are receivedwithin openings 110, 114.

First and second elongated members 102, 104 of extender 100 includedistal faces 124, 126 at distal end 103 of extender 100 that areconfigured to engage at least a portion of proximal faces 46, 54 of bonefastener 32 to further prevent movement of bone fastener 32 relative toextender 100. Accordingly, extender 100 has a length such that distalfaces 124, 126 engage at least a portion of proximal faces 46, 54 whenprotrusions 50, 58 of first and second extensions 48, 56 are receivedwithin openings 110, 114. That is, bone fastener 32 is advanced untilprotrusions 50, 58 of first and second extensions 48, 56 are receivedwithin openings 110, 114 and distal faces 124, 126 engage at least aportion of proximal faces 46, 54, which connects bone fastener 32 withextender 100. In this configuration, bone fastener 32 is restricted frommoving relative to extender 100. It is envisioned that distal faces 124,126 and proximal faces 46, 54 are planar, however other matingconfigurations are possible. It is also envisioned that the elongatedmembers of the extender extend past proximal faces 46 and 54 so that theextender shields the integral connection from stress while the extenderis attached. That is, since the extender is used to manipulate thereceiver, this shielding effect is important so as not to transmit themanipulation forces so as to accidentally break-off the extensions. Thisis shown in FIGS. 2A-2C. In one embodiment, shown in FIGS. 2B-2C, theend of the elongated members slightly wrap around the arms of thereceiver. This not only makes the assembly more rigid but also helps toshield the integral connection from stress.

In one embodiment, surgical system 30 includes a vertebral rodconfigured for manipulation within rod cavity 106 of extender 100 andfixation within channel 44 between first and second arms 40, 42. It isalso envisioned that the vertebral rod may have a size and shape thatcorresponds to the size and shape of rod cavity 106 and slot 57 betweenfirst and second extensions 48, 56 such that the vertebral rod may bemoved along the length of rod cavity 106 and/or slot 57 and into channel44.

In one embodiment, channel 44 of receiver 34 is defined by an innersurface of first and second arms 40, 42 and includes internal threads72, 74 formed on the inner surface of first and second arms 40, 42.Internal threads 72, 74 may be configured to receive a set screw to fixthe position of a vertebral rod within channel 44 of receiver 34. It isenvisioned that internal threads 72, 74 may be reverse angle threads.That is, threads 72, 74 may include a forward face that points down andin toward receiver 34, as disclosed in commonly owned U.S. Pat. No.6,296,642, the disclosure of which is incorporated herein by reference.In one embodiment, the inner surfaces of first and second extensions 48,56 include internal threads which are continuous with internal threads72, 74 formed on the inner surface of first and second arms 40, 42. Inaddition to defining a pathway for implants/instruments, the proximalend can also include features that allow for the attachment of otherinstruments. This feature allows the extender to become part of a largerinstrument system used in spinal and other surgical procedures.

In one embodiment, best shown in FIG. 4, proximal end 101 of extender100 includes a proximal face 128 having a recessed portion 130 formedtherein sized and shaped to provide access for tools and/or boneattachment components. Recessed portion 130 is continuous with rodcavity 106 of extender 100, slot 57 between first and second extensions48, 56 and channel 44 between first and second arms 40, 42 of bonefastener 32 such that sections 130, 106, 57 and 44 define a pathway froman incision in the skin of a patient to a location adjacent a surgicalsite for the delivery o plants, instruments and/or other devices.

In assembly, operation and use, spinal surgical system 30 is employedwith a surgical procedure for treatment of a spinal disorder affecting asection of a spine of a patient, as discussed herein. For example,spinal surgical system 30 can be used with a surgical procedure fortreatment of a condition or injury of an affected section of the spineincluding vertebrae. It is contemplated that spinal surgical system 30,including a rod, is attached to vertebrae to facilitate fusion and/ordynamic stabilization applications of the affected section of the spineas a therapeutic treatment, while providing flexion, extension and/ortorsion capability.

In use, to treat the affected section of the spine, a medicalpractitioner obtains access to a surgical site including a vertebra inany appropriate manner, such as through incision and retraction oftissues. It is envisioned that spinal surgical system 30 may be used inany existing surgical method or technique including open surgery,mini-open surgery, minimally invasive surgery and percutaneous surgicalimplantation, whereby vertebrae is accessed through a micro-incision orsleeve that provides a protected passageway to the area. Once access tothe surgical site is obtained, the particular surgical procedure isperformed for treating the spinal disorder. Spinal surgical system 30 isthen employed to augment the surgical treatment. Spinal surgical system30 can be delivered or implanted as a pre-assembled device or can beassembled in situ. Spinal surgical system 30 may be completely orpartially revised, removed or replaced, for example, removing instrument100, a vertebral rod and/or one or all of the components of bonefastener 32 during or after the surgical procedure.

Bone fastener 32 may be employed as a bone screw, pedicle screw ormulti-axial screw used in spinal surgery. It is contemplated that bonefastener 32 may be coated with an osteoconductive material such ashydroxyapatite and/or osteoinductive agent such as a bone morphogenicprotein for enhanced bony fixation. Bone fastener 32 can be made ofradiolucent materials such as polymers. Radiomarkers may be included foridentification under x-ray, fluoroscopy, CT or other imaging techniques.Metallic or ceramic radiomarkers, such as tantalum beads, tantalum pins,titanium pins, titanium endcaps and platinum wires can be used.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplifications of thevarious embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

Alternate locking mechanisms in accordance with the principles of thepresent invention are shown in FIGS. 3C-3F. In FIG. 3C it is shown thatthe extension protrudes past the proximal end of the extender in orderto lock the extenders into place. In FIG. 3D, a ratchet 29 and tooth 28configuration is provided as a locking mechanism in replace of theprotrusion and recess discussed herein. In FIG. 3E, one side of a ridge25 and groove 26 locking mechanism is shown. In this embodiment, accessto the locking mechanism port 27 is provided on the outside surface soas to provide access to the locking mechanism to allow release of theextender from the elongated member 103. In FIG. 3F, a protrusion 20 islocated on the extender 100 and a hole 22 that mates with the protrusion20 is located on the extension elongated member 103. In this embodiment,the hole 22 can be offset to as to provide access to release the lockingmechanism. Although only one side is shown it is envisioned that thisarrangement can be located on both sides of the bone fastener. Thesefigures show alternate locking mechanisms that can be used in practicingthe bone fastener of the present disclosure and it is envisioned thatother configurations can be used as a locking mechanism withoutdeviating from the principles of the present disclosure.

What is claimed is:
 1. A bone fastener comprising: a receiver defining alongitudinal axis and extending between a proximal end and a distal end,the proximal end including a first wall and a second wall that define animplant cavity, each wall including a proximal face; at least one of thefirst wall and the second wall comprising an extension extendingproximally from the proximal face along the longitudinal axis, theextension including a distal end integral with the proximal face and aproximal end comprising a first locking part configured for fixationwith a second locking part of an instrument; and a bone penetratingmember having a proximal end and a distal end, the proximal end of thebone penetrating member connected with the distal end of the receiver.2. The bone fastener of claim 1, wherein the first and second walls eachinclude an inner surface that defines the implant cavity, the innersurfaces including threads adjacent the proximal faces thereof.
 3. Thebone fastener of claim 1, wherein the extension is monolithically formedwith the first or second wall.
 4. The bone fastener of claim 1, whereinthe extension are configured so as to extend past the proximal face sothat the extender shields the integral connection from stress while theextender is attached.
 5. The bone fastener of claim 1, wherein theextension includes an arcuate surface configuration.
 6. The bonefastener of claim 1, wherein the extension and the first and secondwalls define an integral connection therebetween, the integralconnection includes a relief.
 7. The bone fastener of claim 1, whereinthe extension and the first and second walls define an integralconnection therebetween, the integral connection includes a reducedthickness portion or perforations.
 8. The bone fastener of claim 1,further comprising the first wall comprising a first extension extendingproximally from the proximal face of the first wall and the second wallcomprising a second extension extending proximally from the proximalface of the second wall.
 9. The bone fastener of claim 1, wherein thefirst locking part and the second locking part comprise a cavity and aprotrusion configured for disposal in the cavity.
 10. The bone fastenerof claim 1, wherein the instrument includes an extender.
 11. The bonefastener of claim 1, wherein the instrument includes an inner surfacethat defines an elongated axial cavity configured for disposal of theextension.
 12. The bone fastener of claim 1, wherein the instrumentincludes an extender such that first elongated member and a secondelongated member define a cavity therebetween for disposal of avertebral rod.
 13. The bone fastener of claim 11, wherein the innersurface has an arcuate configuration.
 14. A spinal surgical systemcomprising: a bone fastener comprising a receiver defining alongitudinal axis and extending between a proximal end and a distal end,the proximal end including a first arm and a second arm that define animplant cavity, each arm including a proximal face, the first armcomprising a first extension integrally connected with the proximal faceof the first arm along the longitudinal axis, the first extensioncomprising a locking part, the second arm comprising a second extensionintegrally connected with the proximal face of the second arm along thelongitudinal axis, the second extension comprising a locking part, thebone fastener further comprising a bone penetrating member connectedwith the distal end of the receiver; and an instrument including a firstelongated member and a second elongated member, the first elongatedmember includes an inner surface defining an elongated axial cavityconfigured for disposal of the first arm and a locking part configuredfor fixation with the locking part of the first arm, the secondelongated member includes an inner surface defining an elongated axialcavity configured for disposal of the second arm and a locking partconfigured for fixation with the locking part of the second arm.
 15. Thebone fastener of claim 14, wherein the first and second extensions areconfigured so as to wrap around the first and second arms so thatlateral forces placed on the first and second extensions are transmittedto a head of the bone penetrating member.
 16. The bone fastener of claim14, wherein the extensions and the arms define an integral connectiontherebetween, wherein the integral connections include a relief.
 17. Thebone fastener of claim 14, wherein the extensions and the arms define anintegral connection therebetween, respectively, the integral connectionsincluding a reduced thickness portion.
 18. The bone fastener of claim14, wherein the locking part of the first arm and the locking part ofthe first elongated member comprise a cavity and a protrusion configuredfor disposal in the cavity.
 19. The bone fastener of claim 14, whereinthe locking part of the first arm and the locking part of the firstelongated member comprise a cavity and a protrusion configured fordisposal in the cavity, and the locking part of the second arm and thelocking part of the second elongated member comprise a cavity and aprotrusion configured for disposal in the cavity.
 20. A spinal surgicalsystem comprising: a bone fastener comprising a receiver defining alongitudinal axis and extending between a proximal end and a distal end,the proximal end including a first arm and a second arm that define aU-shaped channel, each arm including a proximal face, the first armcomprising a first extension monolithically formed with the proximalface of the first arm along the longitudinal axis, the first extensioncomprising a protrusion, the second arm comprising a second extensionmonolithically formed with the proximal face of the second arm along thelongitudinal axis, the second extension comprising a protrusion, thebone fastener further comprising a bone penetrating member connectedwith the distal end of the receiver; an extender including a firstelongated member and a second elongated member that define a rod cavitytherebetween, the first elongated member includes an inner surfacedefining an elongated axial cavity configured for disposal of the firstarm and an opening configured for fixation with the protrusion of thefirst arm, the second elongated member includes an inner surfacedefining an elongated axial cavity configured for disposal of the secondarm and an opening configured for fixation with the protrusion of thesecond arm; and a vertebral rod configured for manipulation within therod cavity and fixation within the U-shaped channel.